1. Technical Field
The present invention relates to the treatment of calcium oxalate stone disease.
2. Description of Background Art
Calcium oxalate is the most common constituent of urinary calculi and relatively large crystals of this salt are frequently found in freshly voided urine from patients with recurrent calcium-containing stones. The rate of crystal growth and aggregation of calcium oxalate will determine whether or not a particle large enough to be trapped at some narrow point in the urinary tract can be formed within the transit time of urine through the urinary system. The chance of a particle being trapped depends partly on the size of the particle. The rate of crystal growth may determine to a large extent the subsequent rate of growth of this nidus into a stone. It is well known that several urinary constituents (e.g., pyrophosphate, glycosaminoglycans, citrate) can inhibit the rate of growth and/or aggregation of seed crystals of calcium oxalate in vitro.
Considerable research effort has been and is being expended in an attempt to identify or synthesize compounds that act as inhibitors of calcium oxalate crystal growth and which could be used for treatment of patients suffering from recurrent kidney stone disease. Hydrochlorothiazide, sodium potassium phosphate, and potassium citrate are drugs available for the treatment of calcium oxalate stone disease and reported to reduce its recurrence. These and other drugs available have not been shown to dissolve or remove kidney stones/fragments. The development of drugs more effective in preventing calcium oxalate stone formation and to dissolve kidney stones/fragments is still needed. Since recurrence of stone disease is believed to be largely due to such remnant stone fragments in the kidney, following lithotripsy or other stone removal procedures, their dissolution could dramatically reduce recurrence rates.